Obtaining informed consent is a mandated research practice and is necessary for maintaining the health and safety of all research subjects. Pediatric research requires parents to provide consent on behalf of their children. To respect the developing autonomy of the child, researchers also seek to obtain child assent for research procedures. In longitudinal research, the extent to which a child understands research procedures changes as the child develops. Thus, researchers must take a developmental approach to obtaining child assent.This resource also considers the evolving role of the parent at each stage in the child assent process. We discuss this resource in the context of published child consent guidelines for longitudinal studies, while emphasizing that a developmental approach to assent procedures must account for neurodevelopmental differences. This summary and contextualization of our work is an important step toward encouraging positive and respectful research experiences for children.